Did you adjust in the correct direction ? Usually only takes a small adjustment at a time. As mentioned it won't stop it all together, just at certain speeds. Picture of your lower unit so we can see what you have.Purchased a 18' Kenner center console and if you let go of the wheel it will turn right and keeps turning right. I adjusted the skeg and it made no difference. Any input would be appreciated.
18’ Kenner CC is an outboardIf a outboard ? Some have a friction adjustment to create a centering drag. Are you a inboard engine ?